Test & measurement


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The hunT for dark maTTer


To help explain the formation, evolution and behavior of large-scale structures in the universe such as galaxies, scientists have predicted the existence of dark matter. In fact, theory suggests that the universe may actually contain up to five times more dark matter than ordinary matter! While the question of what actually makes up dark matter remains unanswered, scientists have identified a number of candidate particles. Some of the more promising ones are axions that may be just a ten-trillionth of the mass of an electron. In South Korea, at the Institute for Basic Science (IBS), they have assembled a team of experts to study and try to find axions. A fast PCIe-digitizer by Spectrum Instrumentation was chosen for the latest and most advanced experiments.


phenomenon is done using a haloscope, that in turn uses a fast data acquisition system (DAQ) to capture, analyse and store the results. At CAPP, the Center for Axion and Precision


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Figure 1: This CAPP apparatus is equipped with an 8 T superconducting magnet. The feeble signal (10−24 W) from the cavity is amplified and transmitted through an RF receiver chain with a HEMT amplifier before being sent for acquisition, analysis and storage.


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Physics Research at the IBS, the plan is to conduct a variety of experiments over the coming decade to confirm the existence of axions and ultimately determine their properties. The first experimental results are already in. The team at CAPP has searched for axions with a mass between 6.62 and 6.82 μeV that correspond to the frequency between 1.6 and 1.65 GHz. The search was made using the CAPP apparatus shown in figure 1. The researchers showed experimentally with a 90 per cent confidence level, which is the most


January 2023 Instrumentation Monthly


t is predicted that axions will convert into photons in the presence of a strong magnetic field. So, the Korean team has built a new laboratory that uses super powerful magnets to try and create that precise scenario. Imaging of the


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